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Diphenoxylate/Atropine

Antidiarrheal Opioid Combination
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
1 available
Formulations
2

Mechanism of action

Diphenoxylate activates mu-opioid receptors in the GI tract, reducing peristalsis and increasing transit time. Atropine added in sub-therapeutic doses to discourage abuse.

At a glance

Class
Antidiarrheal Opioid Combination
Schedule
Controlled Substance
Storage
Store at room temperature, protect from light

Dosing

🐕

Dog

Used for non-infectious diarrhea only
Dose
0.1–0.2 mg/kg
Route
PO
Frequency
q8–12h
🐈

Cat

Cats more sensitive to opioid effects
Dose
0.05–0.1 mg/kg
Route
PO
Frequency
q12h

Formulations

💊

Other — 2

Strength
Strength

Storage

Store at room temperature, protect from light

Safety

Monitoring parameters

Stool frequencyResolution within 48hHydration status

Interactions

No documented interactions.

Brands

Other markets

Lomotil

FAQs

Frequently asked questions

What is Diphenoxylate/Atropine?
Diphenoxylate/Atropine is a antidiarrheal opioid combination used in pets. Diphenoxylate activates mu-opioid receptors in the GI tract, reducing peristalsis and increasing transit time. Atropine added in sub-therapeutic doses to discourage abuse.
What is Diphenoxylate/Atropine used for in pets?
Diphenoxylate/Atropine is used in veterinary medicine for: Used for non-infectious diarrhea only; Cats more sensitive to opioid effects.
What is the Diphenoxylate/Atropine dose for dogs?
For dogs, Diphenoxylate/Atropine is typically dosed as follows — Used for non-infectious diarrhea only: 0.1–0.2 mg/kg PO q8–12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the Diphenoxylate/Atropine dose for cats?
For cats, Diphenoxylate/Atropine is typically dosed as follows — Cats more sensitive to opioid effects: 0.05–0.1 mg/kg PO q12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
Does Diphenoxylate/Atropine need a prescription?
Diphenoxylate/Atropine is available over the counter. Even so, you should consult your veterinarian before giving any medication to your pet.

References

References

Textbooks & handbooks

  • Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
  • Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
  • Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
  • National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
  • The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/

Clinical guidelines & consensus

  • Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
  • American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.

Journals & peer-reviewed studies

  • Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
  • Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
  • ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control

Regulatory & approvals

  • Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/

Databases

  • Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →